NUR FARHA SHAAFI - Academia.edu (original) (raw)

Papers by NUR FARHA SHAAFI

Journal of Education and Learning (edisi elektronik)/Journal of Education and Learning, Feb 2, 2025

Springer Proceedings in Materials, 2024

Jurnal Pendidikan Fisika Indonesia, Dec 4, 2023

The misconception related to astronomy is fretfully rising in society. This study aims to investi... more The misconception related to astronomy is fretfully rising in society. This study aims to investigate, (i) level of misconception towards astronomy among university students, (ii) significant difference in students' interest towards astronomy between male and female, (iii) significant difference between science and non-science students' level of knowledge in astronomy, (iv) significant relationship between students' faculties and misconception in astronomy, and (v) significant relationship between the educational background of the respondents' parents and their misconceptions towards astronomy. A qualitative approach was implemented using a set of questionnaires for data collection. The respondents were undergraduate students of with different courses and backgrounds from four different faculties: Faculty of Education, Faculty of Pharmacy, Faculty of Art and Design, and Faculty of Business Management. The data were analyzed using Statistical Package for the Social Science (SPSS). Findings showed that there is a significant difference in students' interest towards astronomy between male and female students, there is a significant different between level of knowledge in astronomy and students' major course, there is significant difference between students' faculties and misconception in astronomy, and there is no significant relationship between the educational background of the respondents' parents and their misconception in astronomy. This study benefits society by clarifying phenomena, distinguishing myth from reality. It aids Science teachers in addressing astronomy misconceptions and helps educators curb their spread.

International Journal of Evaluation and Research in Education, Nov 30, 2023

International journal of evaluation and research in education, Jun 1, 2024

The research focused on the National Planetarium Kuala Lumpur's education programs, investigating... more The research focused on the National Planetarium Kuala Lumpur's education programs, investigating the types and target audiences. It examined the educational theories and strategies used, including multiple intelligence theory and cooperative learning. The study also explored the alignment of astrophysics in Pearson Edexcel International General Certificate of Secondary Education (IGCSE) Physics with the Planetarium's programs. Document analysis and participant observation were employed. The results revealed two program types: on-site and online. The programs showed alignment with IGCSE Physics and utilized theories like social cognitive theory. The National Planetarium positively impacted students through multi-intelligence theory, sociocultural theory, experiential theory, and constructivism. Gamification and group activities enhanced the learning experience. The Planetarium's ability to simulate astronomical events made it an effective medium for instructional science institutions. Overall, the study highlighted the diverse education programs of the National Planetarium Kuala Lumpur, their alignment with IGCSE Physics, and their positive impact on students' personal, physical, and social contexts.

Journal of Language and Communication

This study aims to assess the validity and reliability of research instruments to investigate the... more This study aims to assess the validity and reliability of research instruments to investigate the level of Malaysian students’ participation in E-learning during the COVID-19 pandemic, examine their perceptions towards virtual learning, and propose strategies to increase students’ participation in online classes. The content validity of the research instruments was established by two e-learning experts, while the face validity was examined by seven school students. The adapted questionnaires and interview questions were modified based on the feedback obtained from the two-stage validity process. As for the reliability test, a simple random sampling method was employed, where a Google form was shared with school students with the help of their teachers at a particular school in Tuaran, Sabah, Malaysia. Out of the 43 students, who responded to the questionnaire, 29 were secondary school students while 14 belonged to primary school students; most of them were Year-6 students. Results d...

Graphene, Nanotubes and Quantum Dots-Based Nanotechnology

Journal of Alloys and Compounds

A photovoltaic device with an efficiency that could break the theoretical limit, exceeding ~60% i... more A photovoltaic device with an efficiency that could break the theoretical limit, exceeding ~60% is the focus in the research field in recent years. The efficiency of three important processes in a photovoltaic device need to be ensured to materialize the goal i.e., electron excitations, injections and regenerations. A multiple exciton generation (MEG) mechanism has been proven to increase the photovoltaic conversion efficiency-achievable via usage of small size lead chalcogenides as main light absorber of the photovoltaic device. An efficient electron injection in an excitonic solar cell could be achieved upon fulfilment of the following factors i.e., (i) LUMO fluorophore > CB photoelectrode , and (ii) small offset between the LUMO fluorophore and CB photoelectrode. The opto-electronic properties of lead chalcogenide are tuneable based on its size and morphology. Therefore, a synthesis method that could control the size and morphology of the yielded lead chalcogenide plays an important role. This research investigated the effect of additional activated carbon (AC) to the yielded PbS using vacuum thermal evaporator method. The PbS thin films were fabricated with addition of AC with different surface areas i.e., 80 m 2 /g, 650 m 2 /g and 1560 m 2 /g using thermal evaporator at vacuum pressure of 1.0 × 10-5 Torr. The surface area of the ACs was determined using Micromeritics ASAP 2020 BET (Brunauer-Emmett-Teller). The morphology, elemental analysis, crystal structure, opto-electronic, electron injection efficiency and electrical conductivity of the PbS thin film was characterized using Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-Ray Spectrometer (EDX), X-Ray Diffractometer (XRD), absorption spectrometer, photoluminescence spectrometer (PL), and Bridge Technology 4-point probes (4PP) respectively. The excited and ground states of the PbS, and redox potential of ionLic PMII electrolyte were determined using quantum chemical calculations at b3lyp/lanl2dz level of theory. Three important observations have been made i.e., (i) addition of AC with the PbS reactants affects the yielded morphology of PbS thin film, (ii) bare PbS/TiO 2 device structure offers electron injection efficiency as high as 97% from the PbS to TiO 2 , and (iii) the bare PbS/TiO 2 device structure would offer maximum V OC of ca. 1.7 V, however need to be paired with an electrolyte that possess oxidation potential of ca.-6.5 eV.

Materials Today: Proceedings, 2020

Archetypical excitonic solar cell consists of fluorophore (main light absorber), photoelectrode (... more Archetypical excitonic solar cell consists of fluorophore (main light absorber), photoelectrode (electron transportation), and conducting polymer (electron regeneration). Fluorophore generates excited state electron upon absorption of light with sufficient energy. Electron in the highest occupied molecular orbitals (HOMO) would undergo an excitation to the lowest unoccupied molecular orbitals (LUMO) during the light absorption process. Therefore an electron vacancy in the HOMO of fluorophore is expected; need to be replenished for a continuous process of a photovoltaic mechanism. However the quantum of research on electron regeneration efficiency is still low due to limited computational facility. Two parameters are hypothesized to have significant impact on the electron regeneration process i.e., (i) conductivity (r), and (ii) redox potential (E o) of the conducting polymer. This study aims to establish a correlation between the stated parameters with the photovoltaic conversion efficiency, g. Two conducting polymer were used in this work i.e., (i) alginate, and (ii) a mixture of 60 wt% of carboxymethyl cellulose (CMC) and 40 wt% of polyvinyl alcohol (PVA). The conductivity of the conducting polymer was calculated based on the measured bulk resistance using Electrical Impedance Spectrometer (EIS); showed that r alginate > r CMC/ PVA. The redox potentials were calculated using quantum chemical calculations under the framework of density functional theory (DFT) at the level of b3lyp/lanl2dz. The lead sulphide thin film (fluorophore) was deposited using thermal evaporator on a prefabricated TiO 2 layer on indium-doped tin oxide (ITO) conducting glass. The CMC/PVA-based cell yielded the highest g of 0.0015% under one-sun condition; showed higher g than that of the alginate conducting polymer. Therefore concluded that the conductivity would only determine the speed of the electrons during the regeneration. Nonetheless the efficiency of the regeneration process could be determined by the compatibility analysis of the conducting polymer and fluorophore. The compatibility analysis was carried out based on the energy level alignment between the E o of the conducting polymer, and the HOMO energy level of the fluorophore. The calculated E o of the conducting polymer used i.e., CMC/PVA is À3.144 eV, and alginate is À1.908 eV; incompatible to be paired with the fluorophore (PbS), which the HOMO, and LUMO energy levels are À5.100 eV, and À4.000 eV respectively. The low g of the CMC/PVA, and alginate-based cells however is speculated could also due to energy loss which is equivalent to 1.956 eV, and 3.912 eV energy offset respectively.

Molecular Crystals and Liquid Crystals, 2019

Quantum confined structure-based solar cell is promising two folds increment of the maximum theor... more Quantum confined structure-based solar cell is promising two folds increment of the maximum theoretical photovoltaic conversion efficiency i.e., > 60% in comparison with that of the bulk analogs e.g., silicon-based and dye sensitized solar cell (ca. 32% of maximum theoretical efficiency). The key to the significant increment is the ability of the fluorophore to exhibit multiple exciton generation upon absorption photon with sufficient energy. Small size of lead chalcogenides (PbS, PbSe, PbTe) crystals have been reported and proven experimentally could exhibit this unique property. We have investigated few clusters of narrow bandgap lead chalcogenides nanocrystals i.e., (PbS)n, (PbSe)n and (PbTe)n; which n ¼ 4-80. The cluster models were optimized using quantum chemical calculations to the lowest energy geometry at B3LYP/lanl2dz level of theory. The predicted realistic (PbS) 80 , (PbSe) 50 , and (PbTe) 74 clusters with the size, and bandgap of 4.58 nm (2.00 eV), 4.03 nm (1.51 eV), and 4.84 nm (1.55 eV) are smaller than that of their exciton Bohr radius i.e., 5.01, 13.1, and 24.8 nm respectively. Therefore, the occurrence of multi exciton generation in the clusters is hypothesized upon absorption of photon with E photon ¼ 2E g .

Makara Journal of Technology, 2019

A photovoltaic (PV) mechanism consists of three important steps, i.e., (i) electron excitation up... more A photovoltaic (PV) mechanism consists of three important steps, i.e., (i) electron excitation upon absorption of photon with energy higher than the bandgap of fluorophore, (ii) excited-state electron injection fro m the fluorophore to the photoelectrode, and (iii) electron regeneration fro m the electrolyte to the fluorophore. An efficient electron regeneration could be achieved upon fulfillment of the requirements of energy align ment, i.e., lo west unoccupied molecular orb ital of fluorophore (LUM O fluorophore) > redo x potential of electrolyte > highest occupied molecu lar orbital of fluorophore (HOMO fluorophore). This study investigated the electron regeneration efficiency of excitonic solar cells fabricated using three polymer-based electrolytes, i.e., (i) 60% carbo xy methyl cellulose (CM C) blended with 40% polyvinyl alcohol (PVA), (ii) alginate, and (iii) xanthan. The redo x potentials of the electro lytes (E o) were calculated using quantum chemical calculat ions under the framework of density functional theory. The compatibility of fluorophore and electrolyte was analyzed in terms of the energy level align ment. The cells fabricated using the three polymer-based electrolytes were analyzed, with the CMC/PVA-based cell yielding the highest efficiency, η, of 1.39% under the illu mination of the sun. The low η of the cells can be attributed to the incompatible E o of the electrolytes, which exh ibited a higher energy level than the LUM O fluorophore. The alginate-and xanthan-based cells exh ibited inferior PV propert ies (i.e., open circuit voltage, short circuit current, fill factor, and η) to that of the CMC/PVA-based cell. This finding can be attributed to the increment of energy offset between E o and HOMO fluorophore .

Materials Today: Proceedings